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Background: Assessment of patients for temporal lobe epilepsy (TLE) surgery requires multimodality input, including EEG to ensure optimal surgical planning. Often EEG demonstrates abnormal foci not detected on clinical MRI. 7T MRI provides improved resolution and we investigated its utility to detect potential abnormalities associated with EEG. Methods: Images were acquired on 7T MRI scanner (N=13) in oatients with TLE. Evaluation of 7T imaging for focal abnormalities was performed. Correlation of 7T MRI findings with EEG of focal slowing or interictal epileptic spikes (IEDs) and seizures was performed. Results: Assessment of 7T MRI demonstrated concordance with TLE in 8/13 cases. Three cases exhibited abnormal 7T MRI abnormalities not detected by 1.5 T MRI. Eleven out of 13 cases had EEG findings without anatomic correlates on MRI, with IEDs localizing to contralateral temporal, frontal, and parieto-occipital lobes. 7T images did not reveal focal anatomical abnormalities to account for the EEG findings in these patients. Conclusions: To our knowledge, this is the first study to investigate the role of 7T MRI in relation to EEG abnormalities. 7T RI findings show concordance with clinical data. 7T MRI did not reveal anatomical findings to account for EEG abnormalities, suggesting that such changes may be functional rather than anatomical.
The coronavirus disease (COVID-19) pandemic has had profound consequences on collective mental health and well-being, and yet, older adults appear better off than younger adults. The current study examined mental health impacts of the pandemic across adult age groups in a large sample (n = 5,320) of Canadians using multiple hierarchical regression analyses. Results suggest older adults are experiencing better mental health and more social connectedness relative to younger adults. Loneliness predicted negative mental health outcomes across all age groups, while the negative association between social support and mental health was only significant at average and high levels of loneliness in the 65–69 age group. Results point towards differential mental health impacts of the pandemic across adult age groups and indicate that loneliness and social support may be key intervention targets during the COVID-19 pandemic. Future research should further examine mechanisms of resiliency among older Canadian adults during the pandemic.
The most common treatment for major depressive disorder (MDD) is antidepressant medication (ADM). Results are reported on frequency of ADM use, reasons for use, and perceived effectiveness of use in general population surveys across 20 countries.
Face-to-face interviews with community samples totaling n = 49 919 respondents in the World Health Organization (WHO) World Mental Health (WMH) Surveys asked about ADM use anytime in the prior 12 months in conjunction with validated fully structured diagnostic interviews. Treatment questions were administered independently of diagnoses and asked of all respondents.
3.1% of respondents reported ADM use within the past 12 months. In high-income countries (HICs), depression (49.2%) and anxiety (36.4%) were the most common reasons for use. In low- and middle-income countries (LMICs), depression (38.4%) and sleep problems (31.9%) were the most common reasons for use. Prevalence of use was 2–4 times as high in HICs as LMICs across all examined diagnoses. Newer ADMs were proportionally used more often in HICs than LMICs. Across all conditions, ADMs were reported as very effective by 58.8% of users and somewhat effective by an additional 28.3% of users, with both proportions higher in LMICs than HICs. Neither ADM class nor reason for use was a significant predictor of perceived effectiveness.
ADMs are in widespread use and for a variety of conditions including but going beyond depression and anxiety. In a general population sample from multiple LMICs and HICs, ADMs were widely perceived to be either very or somewhat effective by the people who use them.
The process of creating a Safe and Inclusive Church (SIC) Commission within the Anglican Church of the Province of SouthernAfrica (ACSA) is not unique in the Communion. This article seeks to explore ACSA’s specific journey to date, with a view to engaging the Communion in a learning partnership. While some of the process of establishing this ministry may be unique, there are places of commonality as we jointly grapple with the call of our Lord Jesus to continue to build the Kingdom of God in contemporary times. Most specifically, this process has highlighted a need for renewal of the Church in both our theological understanding and how we organize to best serve our call to preach the Good News. These theological and structural dimensions of ‘doing church’ speak deeply into our ‘being church’ and are at the heart of why dialogue is needed as a Communion. We offer this article as an invitation to continue discerning together how best to follow and serve our Lord and Saviour Jesus Christ by being His Body to a broken and wounded world.
In this chapter we first consider finite element modeling of slender bodies undergoing bending deformation. This will be followed by a discussion on frame structures which can be modeled as an assemblage of slender bodies rigidly connected. First, we will introduce the Bernoulli--Euler theory of beam bending as a review and extension of what is typically covered in an undergraduate sophomore-level course on mechanics of materials. We will then introduce the frame element which can be used to model frame structures deforming in the 2D plane and 3D space.
In this chapter we introduce the concept of an arbitrary virtual displacement which may also be considered as an arbitrary weight function. This will be used to express the equilibrium equation for 3D solids and structures in a scalar integral form. Subsequently, the divergence theorem is applied to transform the scalar integral into another form to which the force boundary condition can be introduced. This results in the statement for the principle of virtual work involving internal virtual work and external virtual work. Internal virtual work and external virtual work will then be expressed in matrix form so that they can be used for the finite element formulation in later chapters. We then consider plane stress and plane strain problems in which the principle of virtual work can be expressed in 2D domains in accordance with simplifying conditions. In the last section, the Lagrange equation is derived within the context of deformable solid bodies, starting from the principle of virtual work.
In this chapter we present the finite element formulation of heat transfer problems which can be used to determine temperature distributions in solid bodies, starting with heat conduction in the 1D domain. Similar to the notion of virtual displacement in earlier chapters, a virtual temperature or an arbitrary weight function is introduced to derive an integral equivalent of the governing equation to which the finite element formulation is applied. Methods for heat conduction and convection, in 1D, 2D, and 3D domains, including time-dependent effects, will be covered. Mathematical equivalence with other scalar field problems is also discussed.
The finite element method is a powerful technique that can be used to transform any continuous body into a set of governing equations with a finite number of unknowns called degrees of freedom (DOF). In this chapter, we will introduce the fundamentals of the finite element method using a system of linear springs and a slender linear elastic body undergoing axial deformation as examples. These simple problems are chosen to describe the essential features of the finite element method which are common to analysis of more complicated structural systems such as 3D bodies.
This innovative approach to teaching the finite element method blends theoretical, textbook-based learning with practical application using online and video resources. This hybrid teaching package features computational software such as MATLAB®, and tutorials presenting software applications such as PTC Creo Parametric, ANSYS APDL, ANSYS Workbench and SolidWorks, complete with detailed annotations and instructions so students can confidently develop hands-on experience. Suitable for senior undergraduate and graduate level classes, students will transition seamlessly between mathematical models and practical commercial software problems, empowering them to advance from basic differential equations to industry-standard modelling and analysis. Complete with over 120 end-of chapter problems and over 200 illustrations, this accessible reference will equip students with the tools they need to succeed in the workplace.
In the finite element formulation, the body is divided into elements of various types. This chapter describes mapping functions for the description of element geometry in the undeformed configuration and shape functions for the description of displacement and thus deformed geometry in the 2D and 3D domains. We introduce the "isoparametric" formulation in which mapping functions and shape functions are identical. This is followed by discussions on integration in the mapped domains and numerical integration.
This chapter deals with the finite element formulation for thin plate and shell structures. We will review the assumptions on the kinematics of deformation from classical plate bending theories, introduce them into the finite element formulation for plates, and then extend the formulation to curved shell structures within the isoparametric formulation. For 3D solid elements that can be used for plates and shell analysis, we will first look at solid elements with three nodes through the thickness. We will then show how solid elements with two nodes through the thickness can be constructed for analysis of plate and shell structures.
In this chapter we first describe how to construct the element stiffness matrix and load vector in 2D domains. The mapping and shape functions derived in the previous chapter are introduced to express strain components in terms of nodal DOF. Extension of the finite element formulation to 3D domains is demonstrated using the eight-node hexahedron as an example. For dynamic problems, the element mass matrix can be formed by treating the inertia effect as a body force applied to the element. The global mass matrix is then assembled to construct the equation of motion for analyses of free vibration and forced vibration. In the last section, we briefly discuss important aspects of finite element modeling and analysis that often arise in 2D and 3D problems where the number of DOF can be large. We discuss issues, such as sparse matrices and mesh generation, which early students of the finite element method may find helpful for future reference.
In this chapter we consider the finite element formulation for bending of slender bodies under a tensile or compressive axial force. In order to capture the effect of axial force we look at the force and moment equilibrium in the deformed configuration, but still assuming small translational displacement and rotation of the cross-section. In the finite element formulation, it is shown that the effect of axial force on bending manifests as an effective bending stiffness. It will be shown that the finite element formulation of a slender body under compressive axial force results in a matrix equation for eigenvalue analysis from which we can determine the static buckling load and the buckling mode. Subsequently, we consider the finite element formulation for vibration analysis of slender bodies to investigate the effect of axial force on the natural frequencies and modes. Finally, we introduce the finite element formulation of slender bodies subjected to a compressive follower force in which the direction of the applied force is always parallel to the body axis in the deformed configuration.